feat(android): support private plugin callbacks and commands (#6863)

Author: lucasfernog

.changes/android-enhance-method-parse.md

@@ -0,0 +1,5 @@
+---
+"tauri": patch
+---
+
+Enhance parsing of annotated Android plugin methods to support private functions.

core/tauri/mobile/android/src/main/java/app/tauri/plugin/PluginHandle.kt

@@ -12,10 +12,12 @@ import androidx.core.app.ActivityCompat
 import app.tauri.PermissionHelper
 import app.tauri.PermissionState
 import app.tauri.annotation.ActivityCallback
-import app.tauri.annotation.PermissionCallback
 import app.tauri.annotation.Command
+import app.tauri.annotation.PermissionCallback
 import app.tauri.annotation.TauriPlugin
 import java.lang.reflect.Method
+import java.util.Arrays
+
 
 class PluginHandle(private val manager: PluginManager, val name: String, val instance: Plugin, val config: JSObject) {
   private val commands: HashMap<String, CommandData> = HashMap()
@@ -130,7 +132,13 @@ class PluginHandle(private val manager: PluginManager, val name: String, val ins
   }
 
   private fun indexMethods() {
-    val methods: Array<Method> = instance.javaClass.methods
+    val methods = mutableListOf<Method>()
+    var pluginCursor: Class<*> = instance.javaClass
+    while (pluginCursor.name != Any::class.java.name) {
+      methods.addAll(listOf(*pluginCursor.declaredMethods))
+      pluginCursor = pluginCursor.superclass
+    }
+
     for (method in methods) {
       if (method.isAnnotationPresent(Command::class.java)) {
         val command = method.getAnnotation(Command::class.java) ?: continue

core/tauri/mobile/android/src/main/java/app/tauri/plugin/PluginManager.kt

@@ -121,7 +121,7 @@ class PluginManager(val activity: AppCompatActivity) {
         plugins[pluginId]?.invoke(invoke)
       }
     } catch (e: Exception) {
-      invoke.reject(e.message)
+      invoke.reject(if (e.message?.isEmpty() != false) { e.toString() } else { e.message })
     }
   }